This invention relates to a system and method for maximizing the energy savings in AC induction motors at every load, more particularly one that uses a digital signal processor that calibrates control lines to determine the most efficient operational characteristics of the motors.
In prior systems and methods related to energy saving motor controllers using control lines of a motor, constant phase angle and/or constant power factor control were used to determine the control lines. This meant that the control lines were horizontal and the motor controllers were not able to control the motor to specific calibrated operating point at every load to maximize energy savings.
Thus, a need exists for a method and system for AC induction motors which controls the motor to a specific calibrated operating point at every load. Operating points taken across all loads will define a control line or a control curve. Furthermore, a need exists for a method and system for AC induction motors which is capable of recognizing when a motor begins to slip and is about to stall and uses that information to determine calibrated control line so as to maximize energy savings at every load.
The relevant patents of prior art includes the following references:
Patent/Ser. No.InventorIssue/Publication Date2008/0100245TurnerMay 01, 20087,288,911MacKayOct. 30, 20077,279,860MacKayOct. 09, 20077,256,564MacKayAug. 14, 20077,211,982Chang et al.May 01, 20077,081,729Chang et al.Jul. 25, 20066,643,149Arnet et al.Nov. 04, 20036,489,742LumsdenDec. 03, 20025,506,484Munro et al.Apr. 09, 19965,350,988LeSep. 27, 1994